An Efficient Girth-Locating Algorithm for Quasi-Cyclic LDPC Codes

Abstract

The parity-check matrix of a quasi-cyclic code can be represented by a polynomial parity-check matrix with a significantly lower dimension. By using this compact representation, we can develop an efficient method for locating the girth of the quasi-cyclic code. The proposed girth-locating algorithm can be well employed to generate quasi-cyclic low-density parity-check codes with large girth